This would be called a trade-of B.
The reason why this is correct is because if you can only build one thing as a company and you decide that building war equipment is more important to you, then you're doing a trade-off between building butter-making machines and army tanks.
The man is probably homeless. The Great Deoression was not caused by reckless spending, it was actually the opposite. Americans were so fearful of losing money, they stopped trusting banks. Banks closed due to bankruptcy and money in circulation decreased. Americans did not want to spend money so employees were cut when companies overproduced. Many could not mortgages and became homeless - because they saved their money instead of spending it
<span>Rapid populations forced them to move</span>